JP2019004012A - Thermoelectric module - Google Patents

Abstract

To provide a thermoelectric module capable of reducing stress occurring at the juncture of a thermoelectric element and an electrode due to thermal expansion of the electrode.SOLUTION: A thermoelectric module 10 includes first and second thermoelectric elements 1P, 1N, a first electrode 21 having a tabular body 211, and joined to the first end faces of the first and second thermoelectric elements 1P, 1N on the first surface of the body 211, a second electrode 22A joined to the second end face of the first thermoelectric element 1P, and a third electrode 22B joined to the second end face of the second thermoelectric element 1N. The first electrode 21 has a first notch 213A formed on the first side 211A in the width direction D, and a second notch 213B formed on the second side 211B in the width direction D. In the width direction D, at least any one of the first and second notches 213A, 213B is formed in a section between the first and second sides 211A, 211B of the first electrode 21.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a thermoelectric module.

  Generally, in a thermoelectric module, an electrode is joined to the end face of a thermoelectric element, and adjacent thermoelectric elements are electrically connected to each other by this electrode. Such a thermoelectric module is described in Patent Document 1, for example. Patent Document 1 proposes a thermoelectric module that can prevent concentration of thermal stress at the four corners of the end face of the thermoelectric element while increasing the area of the electrode joined to the end face of the thermoelectric element.

JP 2014-1112587 A

  As described in the above-mentioned Patent Document 1, when a current is passed through the thermoelectric module, an endothermic phenomenon occurs on one surface of the module to cool the electrode, and a heat dissipation phenomenon occurs on the other surface. As a result, the electrode is heated. In Patent Document 1, it is proposed to prevent concentration of thermal stress by disposing electrodes spaced from four corners of the end face of the thermoelectric element on the heat absorption side.

  However, Patent Document 1 only proposes a technique for preventing thermal stress concentration at the four corners of the end face when the thermoelectric element has a rectangular end face, and proposes a technique for dealing with other thermal stresses. I don't mean. For example, a technique for dealing with thermal stress caused by thermal expansion of an electrode heated on the heat radiation side of a thermoelectric module has not been proposed in the conventional techniques including Patent Document 1.

  In view of the above, one of the objects of the present invention is to provide a thermoelectric module that can reduce the stress generated at the joint between the thermoelectric element and the electrode due to the thermal expansion of the electrode.

  The thermoelectric module of the present invention has first and second thermoelectric elements and a plate-like main body, and the first surface of the main body is the first end surface of the first thermoelectric element and the second A first electrode joined to a first end face of the first thermoelectric element to electrically connect the first and second thermoelectric elements to each other, and a side opposite to the first end face of the first thermoelectric element A second electrode joined to the second end face of the second thermoelectric element, and a third electrode joined to the second end face opposite to the first end face of the second thermoelectric element, One electrode includes a first notch formed on a first side in the width direction corresponding to a longitudinal direction connecting the centers of the first and second thermoelectric elements, and a second in the width direction. A second notch formed on a side of the first electrode and the second side of the first electrode in the width direction. Wherein at least one of said first notch or said second notch is formed in the.

  According to the present invention, since the thermal stress generated by the thermal expansion of the electrode is absorbed by the deformation in the notch portions formed on both sides in the width direction of the electrode, the stress generated at the junction between the thermoelectric element and the electrode is reduced. be able to.

The figure which shows the plasma processing apparatus containing the thermoelectric module which concerns on embodiment of this invention. The figure which shows the example of planar arrangement | positioning of the upper surface side electrode in the thermoelectric module which concerns on embodiment of this invention. The figure which expands and shows the shape of the upper surface side electrode shown by FIG. The figure which shows the state which the thermal stress generate | occur | produced in the upper surface side electrode shown by FIG. The figure which shows the state which the thermal stress generate | occur | produced when the notch part was not formed in the upper surface side electrode as a comparative example with respect to the example of FIG. The figure for demonstrating the definition of the depth and angle of a slit-shaped notch formed in the upper surface side electrode in embodiment of this invention. The graph which shows the relationship between the depth of the slit-shaped notch part defined as shown in FIG. 6, and the stress which generate | occur | produces in an upper surface side electrode. The graph which shows the relationship between the angle which the slit-shaped notch part defined as shown in FIG. 6 defines, and the stress which generate | occur | produces in an upper surface side electrode.

  FIG. 1 is a diagram showing a plasma processing apparatus 100 including a thermoelectric module 10 according to an embodiment of the present invention. The plasma processing apparatus 100 includes a thermoelectric module 10, a chamber 101, a plasma electrode 102, a high frequency oscillator 103, an electrostatic chuck 104, and a water cooling plate 105. In the illustrated example, the silicon wafer 110 is attracted by the electrostatic chuck 104 inside the chamber 101.

  The plasma electrode 102 is disposed so as to face the silicon wafer 110 attracted to the electrostatic chuck 104 inside the chamber 101. The electrostatic chuck 104 adsorbs the silicon wafer 110 on the upper surface (the surface facing upward in the drawing; the same applies to the terms of the upper surface and the lower surface). On the other hand, the thermoelectric module 10 and the water cooling plate 105 are disposed on the lower surface of the electrostatic chuck 104. A pipe 105A is formed in the water cooling plate 105, and a cooling fluid is circulated in the pipe 105A.

  The thermoelectric module 10 is disposed between the electrostatic chuck 104 and the water cooling plate 105, and includes a thermoelectric element 1, an electrode 2, and a polyimide film 3. The thermoelectric element 1 includes P-type thermoelectric elements 1P and N-type thermoelectric elements 1N that are alternately arranged with both end faces facing the upper and lower surfaces of the thermoelectric module 10, respectively. By joining the electrodes 2 to the end faces of the P-type thermoelectric element 1P and the N-type thermoelectric element 1N, the P-type thermoelectric element 1P and the N-type thermoelectric element 1N are electrically connected to each other.

  The electrode 2 includes an upper surface side electrode 21 disposed on the upper surface side of the thermoelectric module 10 and a lower surface side electrode 22 disposed on the lower surface side. In the present embodiment, the first electrode is described as the upper surface side electrode 21 and the second and third electrodes are described as the lower surface side electrode 22 based on the arrangement of the plasma processing apparatus 100 as shown in FIG. In other embodiments, the arrangement of the thermoelectric module 10 may be reversed with respect to the example of FIG. 1, and the first electrode may be a lower surface side electrode and the second and third electrodes may be upper surface side electrodes. Alternatively, the thermoelectric module 10 may be arranged such that the first electrode and the second and third electrodes are not located on both sides in the vertical direction, but are located on both sides in the lateral direction or oblique direction. The polyimide film 3 is disposed on the upper surface side of the thermoelectric module 10, and the upper surface side electrode 21 is bonded to the polyimide film 3. Since polyimide is a material that easily deforms, the upper surface side electrode 21 can thermally expand while deforming the polyimide film 3. On the other hand, the lower surface side electrode 22 is fixed to the substrate on the lower surface side of the thermoelectric module 10.

  The P-type thermoelectric element 1P and the N-type thermoelectric element 1N are alternately connected by electrically connecting the P-type thermoelectric element 1P and the N-type thermoelectric element 1N in which the upper surface side electrode 21 and the lower surface side electrode 22 are different from each other. A series circuit is formed. During operation of the thermoelectric module 10, current can be supplied to the circuit to cause an endothermic phenomenon at the upper surface side electrode 21 and a heat radiation phenomenon at the lower surface side electrode 22. Further, if the direction of the energized current is reversed, the heat dissipation phenomenon can be caused by the upper surface side electrode 21 and the heat absorption phenomenon can be caused by the lower surface side electrode 22. Thus, the temperature of the silicon wafer 110 adsorbed on the electrostatic chuck 104 can be controlled by causing the heat absorption phenomenon and the heat radiation phenomenon.

  In the plasma processing apparatus 100, after the silicon wafer 110 is adsorbed to the electrostatic chuck 104, a reactive gas for generating plasma is introduced from the inlet 101 </ b> A of the chamber 101, and a high frequency is applied to the plasma electrode 102 by the high frequency oscillator 103. As a result, plasma is generated. By this plasma, the silicon wafer 110 is subjected to processing such as etching. Thereafter, the reactive gas is discharged from the outlet 101B of the chamber 101 by evacuation.

  By controlling the temperature of the silicon wafer 110 to the target temperature during the plasma processing as described above, the yield of the plasma processing can be improved. In the plasma processing apparatus 100, the temperature of the silicon wafer 110 adsorbed on the electrostatic chuck 104 is controlled to the target temperature by causing the endothermic phenomenon and the heat dissipation phenomenon in the thermoelectric module 10 as described above.

  FIG. 2 is a diagram illustrating an example of a planar arrangement of the upper surface side electrode 21 in the thermoelectric module 10 according to the embodiment of the present invention. FIG. 2 partially shows a planar arrangement of the upper surface side electrode 21 when the thermoelectric module 10 shown in FIG. In FIG. 2, illustration of the thermoelectric element 1 and the lower surface side electrode 22 is omitted. As shown in the drawing, the upper surface side electrodes 21 are arranged two-dimensionally. Each upper surface side electrode 21 has a plate-shaped main body 211. As will be described later, the body portion 211 is formed with one notch portion 213 on each side in the width direction.

FIG. 3 is an enlarged view showing the shape of the upper surface side electrode 21 shown in FIG. FIG. 3 also shows a P-type thermoelectric element 1P and an N-type thermoelectric element 1N joined to the upper surface side electrode 21. When the direction connecting the centers C _1P and C _1N of the respective end faces of these thermoelectric elements 1 is the longitudinal direction D ₁ , the upper surface side electrode 21 is the _first in the width direction D ₂ corresponding to the longitudinal direction D 1. with the a slit-shaped cutout portion 213A is formed on the side 211A, and a slit-shaped notch 213B formed in the second side 211B in the width direction _{D 2.}

Here, as illustrated, notch 213A, 213B are both extend to the center line CL in the width direction _{D 2} of the upper side electrode 21 (same as the line indicating the longitudinal _{D 1).} That is, the width direction _{D 2,} the section _{S 1} between the first side 211A of the upper surface electrode 21 and the second side 211B, at least one notch 213A or notch 213B is formed. Further, in the example shown, the width direction _{D 2,} a portion of the section _{S 2} between the first side 211A of the upper surface electrode 21 and the second side 211B is notch 213A and the notch 213B Both are formed.

  FIG. 4 is a diagram showing a state in which thermal stress ST is generated in the upper surface side electrode 21 shown in FIG. In the side views of FIG. 4 (b) and FIG. 5 (b), it protrudes from the lower surface of the main body 211 of the upper surface side electrode 21 and is joined to the upper end surfaces of the P-type thermoelectric element 1P and the N-type thermoelectric element 1N, respectively. A pair of pedestals 212 is shown. 4B and 5B, the bottom surface electrode 22A bonded to the lower end surface of the P-type thermoelectric element 1P and the lower surface bonded to the lower end surface of the N-type thermoelectric element 1N are shown. A side electrode 22B is also shown. The lower surface side electrodes 22A and 22B have a main body portion 221 and a pedestal 222 similar to the main body portion 211 and the pedestal 212 of the upper surface side electrode 21. Although not shown, the lower surface side electrode 22A is also joined to an N type thermoelectric element different from the illustrated N type thermoelectric element 1N, and the lower surface side electrode 22B is P different from the illustrated P type thermoelectric element 1P. It is also bonded to the thermoelectric element.

As described above, during the operation of the thermoelectric module 10, the temperature of the silicon wafer 110 is controlled to the target temperature by causing an endothermic phenomenon or a heat dissipation phenomenon in the upper surface side electrode 21. At this time, since heat is exchanged between the silicon wafer 110 and the upper surface side electrode 21 via the electrostatic chuck 104 and the polyimide film 3, the upper surface side electrode 21 also becomes high if the above target temperature is high. . In this case, the body portion 211 of the upper surface electrode 21, while deforming the polyimide film 3 as described above, to thermal expansion along the arrow TE ₁ illustrated. On the other hand, the P-type thermoelectric element 1P and the N-type thermoelectric element 1N joined to the upper surface side electrode 21 are mechanically constrained by being fixed to the substrate via the lower surface side electrode 22, respectively. Therefore, the thermal stress ST is generated in the portion of the upper surface side electrode 21 located between the P-type thermoelectric element 1P and the N-type thermoelectric element 1N.

  However, in the upper surface side electrode 21 of the thermoelectric module 10 according to the present embodiment, the main body portion 211 is formed even when the P-type thermoelectric element 1P and the N-type thermoelectric element 1N are constrained by the deformation of the notches 213A and 213B. The thermal expansion of is difficult to be inhibited. As a result, the generated thermal stress ST is reduced.

On the other hand, FIG. 5 is a diagram showing a state in which thermal stress ST is generated when notches 213A and 213B are not formed in the upper surface side electrode 21 as a comparative example to the example of FIG. In this case, the body portion 211 of the upper surface electrode 21 is thermally expanded along the arrow TE ₂ illustrated, the thermal expansion by P-type thermoelectric elements 1P and N-type thermoelectric element 1N is mechanically constrained Be inhibited. As a result, a large thermal stress ST is generated in the upper surface side electrode 21 located between the P-type thermoelectric element 1P and the N-type thermoelectric element 1N. As shown in the drawing, due to the thermal stress ST, the upper surface side electrode 21 is deformed into an arch shape having a height near the center in the longitudinal direction. By this deformation, the joint P1 between the pedestal 212 of the upper surface side electrode 21 and the upper end surface of the thermoelectric element 1, and the joint portion P2 between the pedestal 222 of the lower surface side electrodes 22A and 22B and the lower end surface of the thermoelectric element 1 are obtained. A large stress (combined stress of tensile stress and shear stress) is generated in.

  Subsequently, a change in stress of the upper surface side electrode 21 due to the formation of the notches 213A and 213B as described above was verified by numerical analysis. Specifically, a notch 213A having a width of 0.3 mm is formed on the upper electrode 21 having a length of 8 mm, a width of 2.9 mm, and a thickness of 0.6 mm (the main body 211 is 0.4 mm and the base 212 is 0.2 mm). , 213B, when the temperature of the upper surface side electrode 21 is fixed at 60 ° C. and the temperature of the upper surface side electrode 21 is vibrated between 60 ° C. and 120 ° C., the base 212 of the upper surface side electrode 21 is formed. And the amplitude of the stress generated at the joint between the thermoelectric element 1 and the end face of the thermoelectric element 1 (joint P2 shown in FIG. 5).

FIG. 6 is a diagram for explaining the definition of the depth d and the angle θ of the slit-like cutouts 213A and 213B formed in the upper surface side electrode 21 in the embodiment of the present invention. As shown, notch 213A, the depth d of the 213B is in the widthwise direction _{D 2} of the upper surface electrode 21, the center line CL and the notch portion 213A, the distance between the tip of 213B. In the following description, the depth d when the tips of the notches 213A and 213B have just reached the center line CL is 0, and d> 0 when the tips of the notches 213A and 213B extend beyond the center line CL. When the tips of the notches 213A and 213B do not reach the center line CL, d <0. In the analysis described below, the notches 213A and 213B are assumed to have the same depth d.

FIG. 7 is a graph showing the relationship between the depth d of the slit-shaped notches 213A and 213B defined as shown in FIG. 6 and the stress generated in the upper surface side electrode 21. As shown in FIG. In the analysis regarding the depth d, the angle θ of the notches 213A and 213B was set to 20 °. As shown in the graph of FIG. 7, in the case of d <0, i.e., notch 213A between the first side 211A of the upper side electrode 21 when viewed in the width direction _{D 2} to the second side 211B In the case where there is a section in which neither of the notches 213B is formed, the amplitude of the stress generated at the joint between the pedestal 212 of the upper electrode 21 and the end face of the thermoelectric element 1 is a relatively large value (d = −0. 64.2 MPa at 20 mm, 63.5 MPa at d = 0.10 mm). In contrast, the case where d = 0, the other words, the cutout portion 213A or section _{S 1} between the first side 211A of the upper side electrode 21 to the second side 211B when viewed in the width direction _{D 2} When any one of the notches 213B is formed, the stress amplitude is smaller than the above case (59.9 MPa). Furthermore, in the case of d> 0, i.e., if the notch portion in a part of the section _{S 2} between the first side 211A to the second side 211B 213A, both 213B is formed, the amplitude of the stress is further (56.0 MPa at d = 0.10 mm, 53.9 MPa at d = 0.18 mm, 54.2 MPa at d = 0.20 mm, 51.7 MPa at d = 0.30 mm).

According to the above results, either from the first side 211A of the upper surface electrode 21 of the second cut-out portion in a section _{S 1} of until side 211B 213A or notch 213B when viewed in the width direction _{D 2} It is effective to reduce the stress generated at the joint between the thermoelectric element 1 and the electrode 2 due to the thermal expansion of the upper surface side electrode 21. Further, the cutout portion in a part of the section _{S 2} between the first side 211A to the second side 211B 213A, by forming both 213B, the thermoelectric element 1 and the electrode due to thermal expansion of the top-side electrode 21 2 can be further reduced.

Referring again to FIG. 6, the cutout portion 213A, the angle θ of 213B, the width direction _{D 2} of the upper side electrode 21, notch 213A, which is the angle between the direction 213B extend. Notch 213A, 213B in parallel to the width direction _{D 2,} i.e. when extending perpendicularly to the longitudinal direction _{D 1,} the angle θ becomes 0. Notch 213A, in the direction 213B is inclined with respect to the width direction _{D 2} and longitudinal _{D 1,} when extending facing each other, the angle theta> 0. Here, when the notches 213A and 213B extend facing each other, the notches 213A and 213B approach each other as they approach the center line CL. On the other hand, the cutout portion 213A, in the direction 213B is inclined with respect to the width direction _{D 2} and longitudinal _{D 1,} if extending back to back with each other, the angle θ becomes <0. Here, when the notches 213A and 213B extend backward from each other, the notches 213A and 213B are separated from each other as they approach the center line CL. In the analysis described below, the notches 213A and 213B are assumed to extend substantially in parallel, that is, at substantially the same angle θ.

FIG. 8 is a graph showing the relationship between the angle θ of the slit-shaped notches 213A and 213B defined as shown in FIG. 6 and the stress generated in the upper surface side electrode 21. As shown in FIG. In the analysis regarding the angle θ, the depth d of the notches 213A and 213B was set to 0.18 mm. As shown in the graph of FIG. 8, if the theta ≦ 0, i.e., notch 213A, if 213B Do extending perpendicularly to the longitudinal direction D _1, or extend back toward one another, the upper surface electrodes 21 The amplitude of the stress generated at the joint between the pedestal 212 and the end face of the thermoelectric element 1 is a relatively large value (θ = −10 degrees, 58.1 MPa, and θ = 0, 57.7 MPa). In contrast, theta> 0, i.e., notch 213A, in a direction inclined with respect to the longitudinal direction D ₁ of the 213B, when extending opposite each other, the amplitude of the stresses, according to the angle theta is larger (55.4 MPa at θ = 10 degrees, 53.9 MPa at θ = 20 degrees, and 52.6 MPa at θ = 30 degrees).

According to the above results, notch 213A, 213B is, in a direction inclined with respect to the longitudinal direction D ₁ of the upper surface electrode 21, may extend to face each other, the thermoelectric element 1 by thermal expansion of the top-side electrode 21 This is effective for reducing the stress generated at the joint between the electrode 2 and the electrode 2.

  In the thermoelectric module 10, the upper surface side electrode 21 has a function of electrically connecting the P-type thermoelectric element 1 </ b> P and the N-type thermoelectric element 1 </ b> N and transmitting heat between the polyimide film 3 and the thermoelectric element 1. Have. Since the upper surface side electrode 21 does not come into contact with the polyimide film 3 in the portion where the notches 213A and 213B are formed as described above, the larger the area occupied by the notches 213A and 213B, the larger the heat that the upper surface side electrode 21 can transfer. The amount decreases. Further, although depending on the depth d and the angle θ of the notches 213A and 213B, the electrical resistance between the P-type thermoelectric element 1P and the N-type thermoelectric element 1N increases as the area occupied by the notches 213A and 213B increases. To do.

Thus, when considered in a plane containing the longitudinal _{D 1} and the width direction _{D 2} of the upper side electrode 21, notch 213A to the area of the upper face side electrode 21 (Sd), the ratio of the total area of 213B (Ss) (Ss It is desirable to determine the shapes of the notches 213A and 213B so that / Sd) is equal to or less than a predetermined value. According to the knowledge of the present inventors, in order for the thermoelectric module 10 to exhibit sufficient performance in the plasma processing apparatus 100 shown in FIG. 1, the notches 213A and 213B with respect to the area (Sd) of the upper surface side electrode 21 are used. It is desirable that the ratio (Ss / Sd) of the total area (Ss) is less than 0.33 (1/3). For example, the ratio (Ss / Sd) of the total area (Ss) of the notches 213A and 213B to the area (Sd) of the upper surface side electrode 21 shown in FIG. 3 is 0.18.

  According to the embodiment of the present invention as described above, it is possible to reduce the stress generated in the joint portion between the thermoelectric element 1 and the electrode 2 due to the thermal expansion of the upper surface side electrode 21 of the thermoelectric module 10.

  In addition, this invention is not limited to said embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.

  For example, in the above embodiment, the upper surface side electrode 21 is bonded to the polyimide film 3 and the lower surface side electrode 22 is fixed to the lower surface side substrate of the thermoelectric module 10, but in other embodiments, the lower surface side The electrode 22 may also be bonded to the substrate via a polyimide film. In this case, since the lower surface side electrode 22 can also be expanded while deforming the polyimide film, by forming a notch similar to the upper surface side electrode 21 on the lower surface side electrode 22, The stress generated at the joint with the electrode 2 can be reduced. In the above case, the notch may be formed in both the upper surface side electrode 21 and the lower surface side electrode 22, or may be formed only in the lower surface side electrode 22.

Further, in the above embodiment, each of the one notch 213A of the first side 211A and second side 211B in the width direction _{D 2} of the upper side electrode 21, but 213B are formed, a first side 211A A plurality of notches may be formed on each of the second side 211B.

  In the above embodiment, the notches 213A and 213B formed in the upper surface side electrode 21 have the same depth d. However, in other embodiments, the notches 213A and 213B have different depths. It may be formed with a height d. Similarly, in the above-described embodiment, the notches 213A and 213B extend at substantially the same angle θ, but in other embodiments, the notch 213A and the notch 213B may extend at different angles θ.

  In the above embodiment, the example in which the cutout portions formed on the first side 211A and the second side 211B of the upper surface side electrode 21 are linear slits has been described, but the shape of the cutout portion is It does not necessarily have to be a linear slit shape. For example, the notch may be a slit or a slit including a bent portion. Alternatively, from the viewpoint of heat transmission and the viewpoint of electrical resistance between thermoelectric elements as described above, as the area closer to the first side 211A and the second side 211B is secured after securing an area other than the notch portion of the electrode. You may form the V-shaped notch part which becomes wide.

  In addition, the present invention may employ other structures or the like as long as the object of the present invention can be achieved.

DESCRIPTION OF SYMBOLS 100 ... Plasma processing apparatus, 10 ... Thermoelectric module, 1 ... Thermoelectric element, 2 ... Electrode, 21 ... Upper surface side electrode, 22 ... Lower surface side electrode, 3 ... Polyimide film, 211A ... First side, 211B ... Second side , 213A ... notch, 213B ... notch, D 1 _... longitudinal, D 2 _... width direction.

Claims (5)

In thermoelectric module,
First and second thermoelectric elements;
A first main surface of the first thermoelectric element is joined to the first end surface of the first thermoelectric element and the first end surface of the second thermoelectric element; A first electrode that electrically connects the two thermoelectric elements to each other;
A second electrode joined to a second end surface opposite to the first end surface of the first thermoelectric element;
A third electrode joined to a second end face opposite to the first end face of the second thermoelectric element;
The first electrode includes a first notch formed on a first side in a width direction corresponding to a longitudinal direction connecting centers of end faces of the first and second thermoelectric elements, and the width direction. A second notch formed on the second side of the
In the width direction, at least one of the first notch part or the second notch part is formed in a section between the first side and the second side of the first electrode. A thermoelectric module characterized by that. In the width direction, both the first notch and the second notch are formed in a partial section between the first side and the second side of the first electrode. The thermoelectric module according to claim 1, wherein: The thermoelectric module according to claim 1 or 2, wherein the first and second cutout portions are opposed to each other in a direction inclined with respect to the longitudinal direction. The thermoelectric module according to any one of claims 1 to 3, wherein the first and second cutouts extend in directions substantially parallel to each other. In a plane including the longitudinal direction and the width direction, the ratio of the total area of the first notch and the second notch to the area of the first electrode is less than 0.33. The thermoelectric module according to any one of claims 1 to 4.

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